On the basis of logging data and seismic data, the Madama Formation of Upper Cretaceous in Termit Basin in Niger was interpretated as a third-order sequence, which includes a lowstand system tract(LST), a transpressive system tract(TST) and a highstand system tract(HST). In this study, four major seismic facies (progradational seismic facies, channel filling seismic facies, parallel to subparallel reflection seismic facies and clutter reflection seismic facies) and one sedimentary facies(braided river delta) have been identified. The LST mainly developed the braided river delta front, the HST mainly developed the braided river delta plain, and the sedimentary evolution of Madama Formation is a regressive process as a whole.

通过对岩石薄片及铸体薄片的观察和分析,结合大量物性及压汞分析资料,对辽河西部凹陷西斜坡沙四段砂岩储层的岩石学特征、成岩作用及储层物性特点进行了研究.结果表明,研究区岩石类型以长石岩屑砂岩和岩屑砂岩为主,常见压实、胶结、交代、溶蚀、蚀变等成岩作用类型;常见孔隙类型有原生粒间孔、粒间溶孔、粒内溶孔等,其中粒间扩大孔隙最常见;孔隙结构主要为细-中孔细喉型,储层类型主要为中孔低-中渗型,储层物性较好.主要分析了成岩作用对储层发育的影响,压实和胶结作用对储层具有破坏性作用,溶蚀作用对改善储层物性具有建设性作用.溶蚀作用形成的粒间溶孔、粒内溶孔、粒间扩大孔及超大孔隙对储层的贡献最大,形成了中-粗孔、中-高渗型优质储层.900～1 900 m和2 300 ～2 900 m深度段为孔隙度和渗透率异常带,带内溶蚀作用发育,在其中寻找有利的储层应当成为下一步勘探的重点目标.

古地貌是控制滩坝沉积的重要因素,决定了滩坝发育的规模与特征.运用印模法与层序地层学相结合的方法,通过残余厚度求取、真厚度校正、压实恢复、潜山剥蚀区确定和古水深恢复5个步骤,恢复辽河西部凹陷曙北地区沙四段层序2低位体系域主要滩坝砂体沉积时期的古地貌,据此分析研究区古地貌对滩坝沉积的控制作用.研究区古地貌总体上呈西高东低,西部为斜坡带,东部为洼陷带,斜坡带中部为古隆起区.根据古地貌特征将曙北地区分为沿岸带、潜山带、北部斜坡带、南部斜坡带和洼陷带5个地貌单元,滩坝砂体主要分布在沿岸带与古隆起周围.古地貌控制了湖盆水体的范围与相对深度、水动力的强弱分带、滩坝沉积的地形坡度、物源的搬运通道与卸载场所等滩坝沉积的影响因素,进而控制滩坝砂体的发育.

This article used sampling method to make a statistical analysis on the life condition,prospects planning and the factors of the students in China University of Geosciences(Beijing),designed to help those who are stepping into society analyze how all aspects in the life of university in? uence their career in the future,enabling them to fi nd out their own advantages in the competition better.Through data analysis,it summarized the impact of the gender,specialty and other factors on career planning,and provides different proposals for different students.